What's the one thing on earth you can add to a great work of art to make it better? A fat cat. The paintings of Botticelli, Rubens, Dali, Titian, and others have been "spruced up" by digital mastermind Svetlana Petrova at Fat Cat Art by inserting a plump orange kitty with a hilarious expression. That's Botticelli's… »9/09/11 4:10pm 9/09/11 4:10pm